Fluorescence spectra of ions in solution

Two types of fluorescence spectra are observed in aqueous solution and in the presence of an excess of cadmium ions. In the absence of any stabilizer the fluorescence is characterized by two very weak bands (41), one centered at 450 nm and attributed to the direct recombination of charge carriers (61) from shallow traps, and the other very broad at about 650 nm, which is not clearly attributed. The presence of a stabilizing agent, such as HMP (59,60), makes it possible to increase the sulfide vacancies at the surface resulting in a more intense fluorescence band, centered in the region of 550 nm. This band is attributed to the recombination of... 

See for example Topics in Current Chemistry, Volume 221 - Contrast Agents I. Carnall, W. T. The absorption and fluorescence spectra of rare earth ions in solution, Handbook on the Physics and Chemistry of the Rare Earths , Vol. 4 Eds. Gschneider... 

However, such is not the case here, and, in fact, we will soon appreciate the amount of extensive studies already made on the absorption and fluorescence spectra of the rare earth ions, both in crystalline matrices and in solution. 

W.T. Carnall, The absorption and fluorescence spectra of rare earth ions in solution 171... 

The Absorption and Fluorescence Spectra of Rare Earth Ions in Solution, W.T. Camall. 

Figure 15.19. Calcium Indicator. The fluorescence spectra of the calcium-binding dye Fura-2 can be used to measure available calcium ion concentrations in solution and in cells. [After S. J. Lippard and J. M. Berg, Principles of Bioinorganic Chemistry. (University Science Books, 1994), p. 193.]...

Hydroxide, aqua, and hydrates. From the similar absorption spectra of Am in aqueous solution, AmCls, and in Lads, and the linear relationship between the decay rate of the americium fluorescence and the number of inner-sphere water molecules, it has been concluded that Am " is coordinated by nine inner-sphere water molecules. Similarly, the hydration number for the Cm ion has been estimated to be nine on the basis of fluorescence lifetimes. EXAFS studies of aqueous Am and Cm, however, have suggested coordination numbers closer to 10. " EXAFS investigation of Cf " " in aqueous solution indicates a coordination number of 8.5 ( 1.5), with a Cf—O distances of 2.41 0.02 A. This coordination number was confirmed for Am in the solid state by isolation of single crystals of the triflate salt of nonaqua complex, which contains a tricapped, trigonal prismatic cation that is isostructural with the analogous Pu" compound. ... 

Fluorescence spectra of several organic molecules and their complexes with metal ions in solutions do not depend on the wavelength of the excitation light, if the wavelength lies... 

The fluorescence maxima of DMOL and MMOL shift to the short-wave region upon their binding the enzyme 20 nm for DMOL and 100 nm for MMOL, and the fluorescence intensity significantly increases (Fig. 3). The observed changes in the fluorescence emission spectra of DMOL can be explained by the increase in hydrophobicity of microenvironment of the emitter on its binding with the protein. Excitation spectrum of MMOL-luciferase complex (Xem=450 nm) corresponds to the absorbance spectra of MMOL-monoanion. In buffer solution we did not seen the fluorescence spectra of this form due to the fact that in water solution electronically excited MMOL-monoanion exists in form of phenolate-ion only (it is in dianion form). The luciferase microenvironment stabilizes MMOL-monoanion by protecting its phenolic group from dissociation. It shows that in vicinity of MMOL bound to... 

The chemiluminescence reactions of the phthalhydrazides (la-g) were carried out in the aerobic DMSO solution in the presence of BuOK. The chemiluminescence intensities relative to the luminol chemiluminescence are also described in Table 1. As expected from their strong fluorescence, If and Ig produced much stronger chemiluminescence than the others. Since their chemiluminescence spectra agreed well with the fluorescence spectra of the corresponding potassium phthalates, the emitters are the phthalate ions (2f and 2g) similar to the luminol chemiluminescence. 

Petek H, Bell AJ, Choi YS, Yoshihara K, Tounge BA and Christensen RL (1995) One- and two-photon fluorescence excitation spectra of the 2 Ag states of linear tetraenes in free jet expansions. J Chem Phys 102 4726 739 Ramasesha S and Zoos ZG (1984) Correlated states in linear polyenes, radicals, and ions Exact PPP transition moments and spin densities. J Chem Phys 80 3278-3287 Raubach RA and Guzzo AV (1973) Singlet-triplet absorption spectrum of uH-trans-retinal. J Phys Chem 75 983-984 Ricci M, Bradforth SE, Jimenez R and Fleming G (1996) Internal conversion and energy transfer dynamics of spheroidene in solution and in the LH-1 and LH-2 light-harvesting complexes. Chem Phys Lett 259 381-390... 

The salts are stable both in the solid phase and dissolved in dry acetonitrile. Absorption and fluorescence spectra of these cation salts in acetonitrile exhibit identical spectral properties as the same cations generated in acidified organic solvents or aqueous acidic solution [7-15]. The photooxidation of the triphenylcarbenium ion has also been studied via its tetrafluoroborate salt [31]. 

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